Monitoring climate change in Western Australia

The Conservation Council of Western Australia has set up a climate change observatory at Charles Darwin Reserve as part of a long-term monitoring project. Charlotte Francis explains how a partnership between two organisations is expected to provide information vital to the long-term management of this reserve.

Bat fauna are one of the indicator species being used in the climate change monitoring. Photo Kurt and Andrea Tschirner.

How do plant and animal populations respond to climate change and what are the implications for long-term biodiversity conservation? This is a complex question, but one which the newly established climate change observatory at Bush Heritage’s Charles Darwin Reserve in Western Australia will help to answer.

The observatory itself consists of an automatic weather station which will monitor changes in temperature, rainfall and solar radiation over time; the project also includes ongoing biodiversity surveys at monitoring points across the reserve.

‘Current conservation planning strategies around climate change are based purely on theory and modelling exercises due to the lack of actual data,’ says Nic Dunlop, Biodiversity Conservation Officer at the Conservation Council of Western Australia (CCWA). ‘That’s how this innovative project came about; we need to establish how climate change will impact and how plants, animals and ecosystems are already responding.’

A joint venture between CCWA and Bush Heritage Australia, Charles Darwin Reserve was chosen as a suitable site for a long-term biodiversity and climate change observatory for a number of reasons.

Straddling the mulga-eucalypt line, the reserve lies on the bio-geographic boundary between the south-western wheat belt and the arid zone in Western Australia. Areas on the boundaries of a bioregion are best placed to show up the types of changes likely to occur under climate change.

Many plant and animal species found here, along with the communities they comprise, are at the edge of their distribution and are therefore particularly vulnerable to the effects of climate change. Current modelling indicates that this area, at the northern edge of the South-West Botanical Province, will become hotter and drier.

As well as being accessible with good accommodation and facilities for volunteers and researchers, Charles Darwin Reserve has favourable conditions for the study. With external factors like weeds, feral animals and other threats to biodiversity minimised, we're more likely to see clearly the results of climate change.

Moreover, with over 90 monitoring sites already set up at the reserve, the CCWA is able to use some of these existing sites for their research and, as a sideline, help Bush Heritage with data collection. ‘This is a great example of two NGOs coming together on a long-term project,’ explains Nic Dunlop, adding that the CCWA biologists will share their findings with Bush Heritage and the community.

‘The exciting thing about the climate change observatory is that it will give us vital information on the capacity of different functional groups of plants and animals to adapt and how they might do it,’ says Hugh Pringle, Bush Heritage ecologist. ‘We can then target vulnerable plants and animals and finetune our management strategies to improve the overall resilience of the land to better withstand the effects of climate change.’

Over a series of six visits, the CCWA have carried out baseline surveys to find out what plants and animals are currently present in the habitats they have selected for monitoring at the reserve. These include five woodland monitoring sites with a focus on two vegetation types:

the northernmost salmon gum and gimlet communities in the wheat belt, and

the southernmost mulga communities in the arid zone.

The next step is to develop a stable of viable climate change indicators.

David Ball, Conservation Council of Western Australia volunteer meteorologist, collecting data from the observatory. Photo Andrea Tschirner.

‘We're choosing indicator species where we have reasonably good information on their ecology, such as perennial plants, ant communities and the bat fauna,’ says Nic Dunlop.

Next spring, CCWA botanists will begin in-depth monitoring of plant communities and their lifecycles to identify how they adapt to climate change. These indicators will then be monitored over the long term and any changes documented.

‘Repeated monitoring over the long term will help to establish whether climate change is causing biodiversity changes at the bio-geographical boundaries and, if so, what are the key species that play an important role in maintaining their stability,’ explains Hugh Pringle.

As the ecological studies relate to climate variables, an automatic weather station, the only meteorological station in this area, was set up at the observatory. As well as continuously measuring temperature, humidity, wind speed, wind direction and rainfall, the station is equipped with a radiometer to measure solar radiation.

At a global level, it's unusual to find such well-developed vegetation as the York and salmon gums and gimlet woodlands in such an arid environment. This may be due to the high water-use efficiency of these large trees under frequent cloudy conditions.

‘If cloud systems start to drift southwards under climate change, it may threaten the long-term viability of these vulnerable communities at their northernmost extent,’ says Hugh Pringle.

With over 90% of native vegetation cleared for agriculture to the south of the reserve, these eucalypt woodlands are one of the largest remnant areas of semi-arid woodland left anywhere in Western Australia, and many plants and animals rely on them for survival.

Working in partnership with researchers, volunteers and university students, this project will provide vital data on how plant and animal species respond in areas affected by rapid changes in climate. In the longer term, the findings will be shared with the wider scientific community and will help inform conservation planning strategies across the region, if not beyond.